»Cosmic rays illuminate the past: calendar-year dating of the Neolithic in the Balkans«

Andrej Maczkowski, Institute of Archaeological Sciences, University of BernOeschger Centre for Climate Change Research, University of Bern

Dendrochronology has played a central role in the absolute dating of prehistoric periods in some regions of Europe. Absolute dating to an exact year of many prehistoric sites has been possible thanks to the decades-long efforts for collecting, measuring, and cross-dating big amounts of archaeological and subfossil wood. On the other hand, no absolute millennia-long tree-ring chronologies exist for the southwestern Balkans. Systematic sampling of archaeological wood within the scope of the EXPLO project has led to the construction of several ‘floating’ tree-ring chronologies from prehistoric sites in the region. Among them are the Mid/Late Neolithic chronologies from the waterlogged site of Dispilio, Greece. The main tree-ring chronologies of oak and juniper wood span for more than 340 years.

Efforts to improve the resolution of the radiocarbon calibration curve led to the discovery several abrupt radiocarbon spikes (SEP- or Miyake events) during the Holocene. A recently discovered Miyake event in absolutely dated tree-ring chronologies from around the world, revealed a sharp spike of radiocarbon in 5259 BC. Annual radiocarbon measurements from Dispilio’s tree-ring chronologies could be matched against the reference data of this new Miyake event, enabling the calendar-year dating of the site without millennia-long tree-ring chronologies. Additionally, the cross-dating of over 240 vertical construction wood elements reveals the spatio-temporal development of the settlement with an annual resolution. Dispilio represents the first calendar-year dated Neolithic site in the wider Eastern Mediterranean region.